A Patient with Noonan Syndrome with a KRAS Mutation Who Presented Severe Nerve Root Hypertrophy.

We report a 45-year-old female with clinical features resembling Noonan syndrome (NS) who presented with significant nerve root hypertrophy. She was initially diagnosed with Charcot-Marie-Tooth disease because her gait disturbance gradually deteriorated and nerve conduction velocity was reduced. However, she did not carry a PMP22 gene mutation. RASopathies are a group of phenotypically overlapping developmental syndromes caused by germline mutations that encode components of the Ras/MAPK signaling pathway. These disorders include NS, cardiofaciocutaneous (CFC) syndrome, and Costello syndrome and are associated with molecular abnormalities in the Ras/MAPK pathway. The patient was suspected to have NS and related disorders because of pulmonary artery stenosis, lymphedema, distinctive facial appearance, and intellectual disability. Genetic analysis identified a heterozygous de novo mutation in KRAS (c.211T>G, p.Tyr71Asp), which is usually observed in patients with NS or CFC syndrome. Although our patient was diagnosed with NS, she revealed clinical manifestations that were typical to CFC syndrome, including intellectual disability. It has been reported that some patients diagnosed with RASopathies with mutations in PTPN11, SOS1, or KRAS developed nerve root hypertrophy. These results suggest that nerve root hypertrophy may be associated with RASopathy, although the onset mechanisms of nerve root hypertrophy are unknown.

[123I]Iomazenil SPECT Detects a Reversible Lesion of the Left Medial Temporal Lobe in a Case of Global Autobiographical Amnesia.

Global autobiographical amnesia is a rare disorder that is characterized by a sudden loss of autobiographical memories covering many years of an individual's life. Generally, routine neuroimaging studies such as CT and MRI yield negative findings in individuals with global autobiographical amnesia. However, in recent case reports, functional analyses such as SPECT and fMRI have revealed changes in activity in various areas of the brain when compared with controls. Studies using iomazenil (IMZ) SPECT with individuals with global autobiographical amnesia have not been reported. We report the case of a 62-year-old Japanese woman with global autobiographical amnesia who had disappeared for ∼4 weeks. [123I]-IMZ SPECT showed reduced IMZ uptake in her left medial temporal lobe and no significant reduction on N-isopropyl-[123I] p-iodoamphetamine (IMP) SPECT in the identical region. Because IMZ binds to the central benzodiazepine receptor, this dissociation between IMZ and IMP SPECT was thought to reflect the breakdown of inhibitory neurotransmission in the left medial temporal lobe. Moreover, when the woman recovered most of her memory 32 months after fugue onset, the IMZ SPECT-positive lesion had decreased in size. Because the woman had long suffered verbal abuse from her former husband's sister and brother, which can also cause global autobiographical amnesia, it is difficult to conclude whether the IMZ SPECT-positive lesion in the left medial temporal lobe was the cause or the result of her global autobiographical amnesia. Although only one case, these observations suggest that IMZ SPECT may be useful in uncovering the mechanisms underlying global autobiographical amnesia.

Significance of N-isopropyl-[123I] p-iodoamphetamine single-photon emission computed tomography in detection of responsible hypoperfusion in hemichorea.

Hemichorea is relatively an uncommon clinical presentation while its known etiology are vascular, metabolic, neoplastic, infectious, autoimmune, and inherited disorders. In the acquired case of hemichorea, the most common cause is the cerebrovascular insult, which is often diagnosed by the magnetic resonance (MR) imaging. An 84-year-old woman reported a one-week history of involuntary movements in the left side of her face and left limbs. Blood tests were normal and brain MR imaging showed no responsible hyperintense lesion on T1-, FLAIR, and diffusion-weighted imaging. N-isopropyl-[123I] p-iodoamphetamine single-photon emission computed tomography (SPECT) detected hypoperfusion in the right thalamus. Further three-dimensional tomography clearly detected the hypoperfusion in the right subthalamic nucleus. The hypoperfused lesion was MR-negative and remained unchanged in SPECT one year after the onset. After the treatment with 0.35 mg of oral haloperidol was initiated, the hemichorea was gradually decreased and completely disappeared in 9 months. Because the three-dimensional analysis performs voxel-by-voxel analysis, it possibly detects the precise hypoperfusion in a specific region. In conclusion, evaluation of cerebral blood flow using SPECT on patients presenting with acute hemichorea can lead to the detection of responsible lesion when the routine examinations are negative.

Simultaneous Oculomotor and Facial Nerve Palsies in a Patient with Systemic Lupus Erythematosus and Sjögren's Syndrome.

A 70-year-old man with systemic lupus erythematosus (SLE) presented with simultaneous right oculomotor nerve palsy and right facial nerve palsy. Brain magnetic resonance imaging and cerebrospinal fluid analysis revealed no abnormality. Coexistent Sjögren's syndrome was diagnosed on the basis of anti-SS-A antibody positivity, salivary gland scintigraphy, and histological findings on minor salivary gland biopsy. As there was no obvious cause of multiple cranial neuropathies, we supposed that the palsies were induced by either of the underlying diseases. The patient was treated with a high-dose of prednisolone and intravenous cyclophosphamide, and both palsies recovered almost completely within two weeks.

Neurosarcoidosis Occurring 6 Years after Onset of Vogt-Koyanagi-Harada Disease.

A 43-year-old Japanese woman visited a clinic with a 2-week history of visual loss, hyperemia, and bilateral eye pain. Dilated fundus and optical coherence tomography showed hyperemic optic disc and multifocal serous retinal detachments. Fundus fluorescein angiography revealed optic disc leakage and numerous hyperfluorescent pinpoints of leakage, which are typical of Vogt-Koyanagi-Harada disease (VKHD). She also showed tinnitus, poliosis, and alopecia. With a diagnosis of VKHD, steroid therapy was started. At the age of 48, oral prednisolone was tapered off, and only corticosteroid eye drops were continued. Eighteen months later, dysesthesia appeared in the left side of her face and in her left ring and little fingers, which spread to the ulnar side of her forearm. Blood tests indicated elevated serum angiotensin-converting enzyme (ACE) levels. Chest CT showed bilateral lymphadenopathy, and histological analysis of the subcutaneous mass in her right arm showed multinucleated giant cells. Steroid therapy was started under a diagnosis of sarcoidosis. Serum ACE and lysozyme levels decreased in response to steroid therapy. We report a case of the concurrence of VKHD and sarcoidosis, which may share a common pathophysiology. Accumulation of further similar cases is necessary to elucidate the precise mechanism underlying the concurrence of these two diseases.

A Successfully Treated Case of Gastrointestinal Stromal Tumor Causing Severe Anemia and Localized Peritonitis Showing Angina Pectoris Resulting in Watershed Cerebral Infarction.

Ischemic stroke following acute myocardial infarction is a rare but a serious complication. Because the pathophysiology of stroke is dynamic, it is often hard to identify the cause of stroke. Here, we present the case of a 75-year-old man with ischemic stroke following angina pectoris caused by severe anemia and localized peritonitis due to gastrointestinal stromal tumor of small intestine. On admission, he showed consciousness disturbance, fever, and left hemiplegia. The electrocardiogram on admission showed ST-segment depression in V2 to V6 which was normalized 4 hours later. The ultrasound cardiogram showed the mild hypokinesis in the apical portion of left ventricle which was also normalized later. The magnetic resonance imaging and angiography showed ischemic stroke in watershed area between right anterior and middle cerebral arteries area and stenosis of distal portion of right middle cerebral artery. The computed tomography of abdomen showed a mass of small intestine. We decided to perform curative surgery after transfusion and successfully resected the mass of the small intestine, which was revealed to be a gastrointestinal stromal tumor (GIST). This is a successfully treated case of GIST in which the complicated pathophysiology of watershed cerebral infarction following angina pectoris might be clearly revealed.

The Rapid Effectiveness of Minocycline against Scrub Typhus Meningoencephalitis.

Scrub typhus is associated with various clinical symptoms. However, the pathogenesis of scrub typhus infection remains to be elucidated. A 73-year-old man was admitted to our hospital with consciousness disturbance and suspected meningoencephalitis. The patient's laboratory data showed deterioration and were indicative of hemophagocytic lymphohistiocytosis (HLH). A whole body examination to detect the trigger disease revealed an eschar, which is a characteristic of scrub typhus, on his back. His symptoms showed dramatic improvement after the administration of minocycline (MINO). This case report highlights that the clinical course of a case of scrub typhus meningoencephalitis that was cured with MINO.

A lethal intracranial Rosai-Dorfman disease of the brainstem diagnosed at autopsy.

Rosai-Dorfman disease (RDD) is a benign histiocytic proliferative disorder characterized by the accumulation of histiocytes in lymph nodes and various other organs. RDD seldom involves the central nervous system, and cases of purely intracranial RDD are particularly rare. We report a case of purely intracranial RDD involving the brainstem that was diagnosed at autopsy. A 68-year-old woman visited our hospital because of visual disturbances and loss of energy. Magnetic resonance imaging revealed an obscure mass in the brainstem. Despite exhaustive work-ups, the etiology of the intracranial mass remained unclear. The patient died of respiratory depression, and an autopsy was performed for pathological investigation. Macroscopically, a pink pale mass 2.5 cm in diameter was found in the brainstem, with no attachment to the dura. Histologically, it was composed of histiocytic cells with incorporation of small lymphocytes (emperipolesis). Immunohistochemical staining revealed that the cells were positive for CD68 and S100 and negative for CD1a, consistent with a diagnosis of RDD. Purely intracranial RDD is extremely rare and considered benign. To date, nine cases (including ours) have been reported. To our knowledge, this is the first case of intracranial RDD with autopsy. Although generally considered benign, RDD involving the brainstem might be lethal.

[Food-borne botulism].

Botulism is a neuroparalytic disease caused by neurotoxins produced by Clostridium botulinum, and classically presents as palsies of cranial nerves and acute descending flaccid paralysis. Food-borne botulism is the most common form of botulism, and caused by preformed neurotoxins produced by Clostridium botulinum. Electrophysiological studies play an important role in the early diagnosis. Confirmation of the diagnosis is based on the detection of botulinum toxins in the patient's serum or stool. In Japan, decades ago, botulism type E occurred, though only sporadically, almost every year, but in recent years, has dramatically decreased in frequency. Botulism is a curable disease when treated early and adequately. Differential diagnosis of cranial nerves and limb muscle palsies with rapid exacerbation should include food-borne botulism.

[Food-borne botulism].

Botulism is a neuroparalytic disease caused by neurotoxins produced by Clostridium botulinum. Food-borne botulism is a kind of exotoxin-caused food intoxication. Although this disease is rarely reported in Japan now, it is a cause of great concern because of its high mortality rate, and botulism cases should be treated as a public health emergency. Botulism classically presents as acute symmetrical descending flaccid paralysis. Its diagnosis is based on the detection of botulinum toxins in the patient's serum or stool specimens. Electrophysiologic tests of such patients show reduced compound muscle action potentials (CMAPs), low amplitudes and short durations of motor unit potentials (MUPs), and mild waning in repetitive low-frequency stimulations. Single fiber electromyography (EMG) is particularly useful for the diagnosis of botulism. We report a case of food-borne botulism that we had encountered. An 83-year-old man with rapidly progressive diplopia, dysphagia, and tetraplegia was hospitalized; he required intensive care, including artificial ventilatory support. Electrophysiologic tests yielded findings compatible with botulism. We made a clinical diagnosis of food-borne botulism and administered antitoxin on the seventh disease day. The patient's motor symptoms started ameliorating several days after the antitoxin injection. Subsequently, botulinum toxin type A was detected in the patient's serum specimen by using a bioassay, and the type A gene and silent B gene were detected in his serum specimen by using polymerase chain reaction (PCR). C. botulinum was also obtained from stool culture on the 17th and 50th disease days. Botulism is a curable disease if treated early. Although it is a rare condition, it should always be considered in the differential diagnosis of patients with rapid onset of cranial nerve and limb muscle palsies.

[Incomplete Gerstmann syndrome with a cerebral infarct in the left middle frontal gyrus].

A 65-year-old right-handed man noted a sudden onset of numbness and weakness of the right hand. On the initial visit to our hospital, he showed severe acalculia, and transient agraphia (so called incomplete Gerstmann syndrome) and transcortical sensory aphasia. Brain MRI revealed a fresh infarct in the left middle frontal gyrus. The paragraphia and aphasia improved within 14 days after onset, but the acalculia persisted even at seven months after onset In an 123I-IMP SPECT study, the cerebral blood flow (CBF) was found to be decreased in the infarction lesion and its adjacent wide area, the ipsilateral angular and supramarginal gyri, and contralateral cerebellar hemisphere. We speculate that inactivation in the infarction lesion caused the CBF decrease in the non-infarcted areas due to diaschisis. This case indicates that Gerstmann syndrome can be caused by not only dysfunction of the angular gyrus but also of the left middle frontal gyrus in the dominant hemisphere.

Electrophysiological signs and the prevalence of adverse effects of acetylcholinesterase inhibitors in patients with myasthenia gravis.

The aim of this prospective study was to assess whether extra discharges (EDs), sometimes following the compound muscle action potential, could be used as a neurophysiological indicator of overdose of acetylcholinesterase inhibitors (AChEIs) in patients with myasthenia gravis (MG). The characteristics and frequency of EDs were explored and the correlation of EDs with cholinergic side effects was also determined. Twenty-two MG patients (14 women, 8 men; 61 +/- 16 years of age) with daily AChEI treatment were examined. The mean disease duration was 10 years (range 2-62 years) and all patients had been treated with AChEI since MG onset. Both single and repetitive stimulation of the ulnar and accessory nerves were performed before and 60 min after oral pyridostigmine bromide (PB) administration and after additional edrophonium injection. Fatigue, side effects, and AChE activity in blood were assessed before and 60 min after PB intake. The daily dose of PB ranged from 150 to 900 mg/day. Fourteen patients (64%) experienced daily cholinergic adverse effects, and muscarinic side effects correlated with AChE activity. Eleven patients (50%) developed EDs after oral PB. Among the eight patients with daily nicotinic side effects, EDs were significantly (P < 0.05) more common. Additionally, older patients were more prone to develop cholinergic side effects and EDs. Thus, when EDs are found, patients should be asked about daily muscular symptoms, which may be related to AChEI treatment and not solely to MG.

[An autopsy case of origin-unidentified meningeal carcinomatosis presenting with monoradiculopathy multiplex in the lower extremities].

A 54-year-old man with a history of partially dissected epidermoid cyst in the left cerebellopontine angle suffered from a slowly progressive dysesthesia and weakness in the lower extremities and trunk. Neurological examination revealed segmental muscular weakness and sensory disturbance in those regions, giving rise to the possibility of monoradiculopathy multiplex, as well as loss of tendon reflexes, dysuria and right facial nerve palsy. Electrophysiological studies indicated irregular motor axonopathy or neuronopathy and interruption of more central sensory pathways than the lumbosacral spinal nerve roots with spared peripheral sensory nerves. Although MRI demonstrated enhanced lesions in the cauda equina and lumbosacral leptomeninges, CSF cytology or a cauda equina biopsy showed no malignancy. His symptoms gradually progressed and he died 15 months after the onset. The autopsy failed to reveal any tumors in the general systemic internal organs. Histopathology demonstrated meningeal carcinomatosis with squamous-type carcinoma cells scattered in the cerebrospinal leptomeninges, and perineurium in almost all the spinal and cranial nerve roots, causing severe axonal degeneration. The dorsal root ganglions escaped tumor cell invasion. Absence of the malignant tumors in the systemic organs and the history of the operated epidermoid cyst indicate that the tumor may be the cause of the meningeal carcinomatosis in this case. Meningeal carcinomatosis almost always shows rapid progression and extremely poor prognosis with several month survival in general, and little attention has been paid that it can exhibit symptoms and signs of segmental involvement in the lumbosacral regions. Our present case prompts us to bear in mind that patients with this condition can survive fairly long, and raises the possibility that a careful neurological examination with segmental involvement will reveal such a feature more frequently than considered so far in this condition.